精密磨床砂轮主轴部件修复后，第一次试运转所用润滑油为（）
A.二号锭子油
B.二号锭子油与煤油各半
C.90％煤油加10％二号锭子油
参考答案：B
Months ago we sailed ten thousand miles across this open sea, which ________ the Pacific,
and we met no storms. [ ]
A. was called
B. is called
C. had better called
D. has been called
为避免剪切和手气割时钢料边缘发生微细裂纹及局部损坏造成（）现象，切割后四周边缘均应加以修正。
